Core C, the Genetics Core, is designed: 1) To establish immortalized lymphoblast cell lines from blood samples from all participants in the Program Project. 2) To generate genotypes for APOE and other genetic risk factors associated with familial AD (FAD), using DNA extracted from the blood samples and lymphoblast cell lines. 3) to provide genetic data to the Core Data Base so that it can be combined with other data in the Program Project (e.g., neurosychologyical test scores, SPECT, fMR, etc.) to predict development of AD in subjects at risk for disease.